


Host

by gracefuldean



Category: Supernatural
Genre: Alternate Universe, Anal Fingering, Anal Sex, Barebacking, Coming Untouched, Dark, Dirty Talk, Established Castiel/Dean Winchester, Light Masochism, M/M, Married Castiel/Dean Winchester, Other Additional Tags to Be Added, POV Dean Winchester, Rough Sex, Spanking, Top Castiel/Bottom Dean Winchester, but that's about to change, dean and cas don't know anything about monsters or the supernatural, dean/other - Freeform, except it's not really Cas, shapeshifter!Cas
Language: English
Status: In-Progress
Published: 2020-02-05
Updated: 2020-02-05
Packaged: 2021-02-28 02:08:45
Rating: Explicit
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 1
Words: 4,073
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22566052
Author URL: https://archiveofourown.org/users/gracefuldean/pseuds/gracefuldean
Summary: What if the person next to you isn’t who you think it is?
Relationships: Castiel/Dean Winchester, Dean Winchester/Other(s)
Comments: 4
Kudos: 36





	Host

**Author's Note:**

> this is a dark fic. heed the tags. 
> 
> also, this is an unbetaed work. don't hesitate to let me know if you spot any mistakes.

Dean is almost asleep when Castiel shifts from his side of the bed.

“Dean?”

Lying on his side with his back to Cas, Dean grunts into his pillow in response, too tired to form words.

“Did you hear that?” Cas asks.

“Hm?”

“I thought I heard a noise from downstairs.”

“It’s probably the heater,” Dean mumbles. “Y’know how noisy that old thing gets sometimes.”

“Maybe.” Castiel doesn’t sound convinced. “I’ll go check it out, make sure it’s still in one piece.”

The sheets rustle quietly when Castiel slides them off himself, making the mattress bounce slightly as he gets up. Dean hears the muted, soft pad of his feet as he rounds their bed, and then Cas is grabbing the covers by his waist, pulling them over Dean until they cover his bare shoulders. Dean opens his eyes when he feels Castiel’s fingers on his skin, their bedroom dark with the deep shadows of the night, but he manages to grab a handful of Castiel’s shirt and pull him down to press a kiss against his lips. Castiel smiles, lips soft and warm where they meet Dean’s, and Dean mirrors it as they share a brief, lazy kiss.

Castiel pulls away, too soon. “I’ll be right back.”

Before Cas can slip out of reach, Dean grabs him by the wrist, sliding his fingers down to wrap around Castiel’s hand. He runs the pad of his thumb over Cas’ slim fingers, feeling the cool, metallic shape of his ring under it. “Just make sure _you_ come back in one piece, alright?,” Dean says with humor. “I’d really hate to have to get corner guards for you. Tragically, I can’t find any that match our furniture.”

He can barely see his husband's face in the dark, but Dean knows from pure instinct that Cas just gave him one of his dramatic yet endearing eye rolls before answering. “Your concern for my well-being is quite touching, sweetheart,” Cas says dryly. “And even though I’d love nothing more than getting a matching bruise on my other hip, do me a favor and kindly inform me beforehand the next time you decide to move our furniture around,” he adds with mild sarcasm, but Dean can hear the amusement behind it.

Dean huffs a laugh at that, grinning as he remembers Castiel’s rather comical mishap a few nights ago. He’d been plenty startled when he heard a loud crash and Castiel cursing immediately afterwards, only to find a grumpy-looking Cas clutching at his hip and staring daggers at the console table when he rushed downstairs. Cas had gotten a sizable, painful-looking bruise from somehow walking into the piece of furniture, and the area had been tender ever since. 

“Cas, I swear I didn’t touch it,” Dean insists with an amused tone.

“It’s always been five paces from the door, not four.”

Now it’s Dean’s turn to roll his eyes. “Cas, you’re killing me,” he groans. “We’ve already been over this. Just turn the lights on, okay?”

“There’s no need if I already know where everything is.”

“Well, I think your memory is failing you then, old man. Good thing you’ve got a handsome husband to take care of you.”

“Yeah, lucky me,” Castiel sighs, but he leans down to press another kiss to Dean’s lips. “Sleep, Dean. I’ll be back in a minute.” He squeezes Dean’s hand before pulling away, and Dean burrows further into the covers with a small smile of his own as he listens to Cas’ retreating footsteps.

He must’ve drifted off before Castiel returned, waking up when the lamp on Castiel's nightstand suddenly clicks on. The dim light bathes the room with a soft, warm glow, but Dean squints drowsily at the unexpected brightness. Eyelids still heavy with sleep, as is the rest of his body, Dean mumbles into his pillow instead of twisting around to face Cas, “Babe, turn the light off. I’m tryin’ to sleep here.”

Castiel doesn’t answer. Instead, Dean feels the mattress dip under his weight when he climbs back on, shifting to get under the covers. He then moves closer, pressing himself against Dean’s back and wrapping an arm around his waist, pulling Dean flush against his chest.

A small, sleepy smile teases the corners of Dean’s mouth when Castiel noses along the back of his neck, breathing in the scent of his skin. Distractedly, Dean realizes that Cas isn't wearing his clothes anymore, but he pays it no mind as Castiel brushes his plush lips over his skin enticingly, the drag of his mouth making Dean’s groin tingle with growing arousal. Cas then runs his hand over his waist, his chest, anywhere he can reach, and his wandering fingers send shivers of pleasure down Dean’s spine. He grips Dean’s hip, the touch almost possessive, and then rolls his own hips against Dean’s backside, pressing his erection along his clothed ass.

Dean lets out a small chuckle when Castiel’s intentions become clear, voice thick with sleep and arousal, “Up for a midnight booty call, Cas? Can’t wait ‘til morning to fuck me?”

Castiel rocks his hips again, more forceful this time, and a small moan slips from Dean’s lips at the sensation. He’s almost fully awake now—the feeling of Castiel pressed along his back and rutting steadily against him rousing him from sleep and turning him on, his own cock twitching as it hardens inside his pajama pants. Castiel mouths along the side of his neck, and Dean stretches to allow him more room, breathing heavily when Cas kisses and licks the sensitive skin. His lips close around a spot below his ear and Castiel sucks a mark into the skin, making Dean groan and lift a hand back to grasp at the soft, dark hair of Castiel’s head, holding on to him as he brings the blood just under the surface. Dean loves his pleasure mixed with some pain, loves to blur the thin lines between the two sensations until he comes apart, and Castiel knows exactly how to do it, indulging him from time to time.

Castiel slides his hand down, past the waistband of Dean’s pants until his palm is pressing against his hard cock. He grips it through the fabric, and Dean gasps at the welcome contact, squeezing his eyes shut as another spike of pleasure runs through him.

“Fuck yeah, Cas,” Dean breathes as Castiel starts stroking his cock, sliding his own erection between Dean's cheeks to the same rhythm. “You feel so good, baby.”

Castiel continues to stroke and rut into him for endless minutes, working Dean up until he feels he might burst with need. His movements are restricted by Castiel’s hold on him, but Dean manages to crane his neck just enough to press their mouths together. Castiel parts his lips immediately, deepening the kiss, and Dean moans loudly when their tongues slide together, licking into the heat of his mouth as he pulls lightly on Castiel’s hair, the dark strands slipping between his fingers.

Castiel groans in response, kissing Dean with renewed fervor and squeezing his hand around his cock until Dean breaks the kiss with a sound closely resembling something between a whimper and a moan.

“Cas, _please_ ,” he begs, desperate with need.

“I know. I’ll give you what you want,” comes Castiel’s answer, spoken softly against the shell of Dean’s ear, which he then catches between his teeth, teasing the flesh.

Dean moans again, and Castiel pulls away, leaving Dean panting and hard on his side of the bed. The drawer slides open and then shut, and then Cas is back in Dean’s space, gently pushing on his shoulder until Dean turns fully over, lying down on his belly. Castiel manhandles him to his liking, throwing the covers off them and tossing his pillow to the side so Dean can lie completely flat on the bed, arms stretched over his head. His cock is trapped between the mattress and his belly, the drag of his sensitive head against the sheets sending a rush of pleasure up his shaft.

He sighs contentedly when Castiel’s hands return to him, palms running slowly down the expanse of his back, caressing the warm skin. Cas’ fingers hook under the elastic band of his pants, sliding the garment off Dean’s body until he’s left naked, bare to his husband’s gaze.

Dean feels Castiel’s eyes on him like a touch as he settles behind him. Impatient and determined to speed things along, Dean cants his hips up in open invitation. “C’mon, Cas. I thought you wanted to fuck me,” he goads, throwing a provocative look at Castiel from over his shoulder. “Or do you just want to watch tonight? I could get the dildo, fuck myself with it if you want.”

Castiel brings his hand down on one of Dean’s asscheeks as soon as the words are out of his mouth, the sharp sound echoing around them before Dean registers the stinging, satisfying sensation it leaves behind. Dean moans needily at the pain radiating from his ass, fingers clutching the fitted sheet of their bed as a rush of endorphins flood his system.

Castiel hums with approval. “You need it that bad, sweetheart?” he asks, voice growing lower with each word and going straight to Dean’s groin. He grabs Dean by the hips, tugging him up and backwards, and Dean folds his legs under himself, bracing his weight on his forearms and staying low. With a tap to his inner thigh from Castiel, Dean widens his stance by sliding his knees away from each other, spreading himself for Cas. There’s something about being like this for Cas that never fails to arouse Dean even more, the feeling of being so exposed and vulnerable sending a thrill down to his body. He bites his lip, stifling a needy groan as his cock and balls hang heavily under him, enjoying the way the cool air in the room feels between his parted cheeks. 

The lube cap snaps open with a click, making Dean’s heart beat wildly with anticipation. "Look at you, all needy and desperate and so eager to please." Cas hums again before continuing, "But that's not quite all of it, is it? You just want something inside you, want something to make you feel good, and you'll take anything, won't you? Do you want—do you _need_ a cock in your ass to feel good, Dean?" Castiel's lips brush the shell of his ear, Dean shivering at the feeling, "Want me to fuck you until it’s all you can feel, until I fill you up, make your hole drip with my come?”

Dean can’t hold himself back anymore. He lets out a whimper at Castiel’s words, arousal pumping through his veins at the obscene image his mind conjures, and then gasps as cold lube is dribbled generously between his cheeks, running down until it coats his rim.

Castiel’s hand closes around the base of his cock and squeezes him again, just the way Dean likes it, and the sudden rush of pleasure-pain clears his head enough for him to answer, “Yes, Cas! I want it, I _need_ you.”

Satisfied, Castiel lets up, his touch turning gentler as he gives Dean a few strokes. He fondles Dean’s sack for a bit before he lets the pad of his finger brush along his perineum, gathering the lube that had trickled down. He presses the tip of his finger at Dean’s entrance, eliciting yet another breathy moan from him as Castiel circles the tight ring of muscle, spreading the lube around. He then pushes the rest of his finger inside, and Dean relishes the faint burn it brings, welcomes it by spreading his thighs further apart and arching his back.

Cas slides his finger out, and then in again, pumping it into Dean’s hole a few times before he adds a second. Dean groans at the delicious stretch, a bead of precome oozing from his slit, and his hole instinctively twitches and tightens around Castiel’s fingers, pulling them in. 

Castiel exhales loudly. “Fuck, Dean,” he says, awed, and thrusts both fingers inside Dean again. “You’re so beautiful like this. The way your greedy little hole just,” Castiel slides his fingers out of him, pushing them back in slowly, and Dean has no doubt that Cas is watching the way his slick rim pulls them into his body, “sucks them right in.” Castiel groans, deep, and drives his fingers back inside him with a powerful thrust, making Dean moan wantonly at the roughness. “You are truly meant for this, baby.”

Cas starts finger fucking him in earnest, effectively turning Dean into a mess of arousal and need. Dean pants as Castiel opens him, rocking his hips back to meet each thrust. Cas spanks him again, harder, and Dean clenches around him in response, biting his lip as the sting heightens his pleasure. He takes his time fingering and teasing Dean, withdrawing his fingers from his body after he’s stretched to his liking, and Dean whimpers softly at the loss as he’s left empty and wanting.

Castiel soothes him quickly, stroking his palm over the flesh he’d abused. His skin feels warm and tingly under Cas’ hand. “Shh, I’m still here. I got you,” he says softly, and Dean melts into the touch. The lube cap snaps open again, Castiel’s touch disappearing briefly as Dean hears him slick his cock. His hands return, settling around Dean’s hips, and then Cas is shifting behind him, drawing closer to Dean until the tip of his cock nudges at his entrance.

Dean moans lowly as Castiel pushes the head of his cock in, breaching him. Castiel then gives a few shallow thrusts, letting Dean adjust before he sinks into him in a smooth, slow glide, both men groaning in unison when Castiel finally bottoms out. Precome flows steadily from Dean’s slit now, leaving a damp spot on the bedding underneath, and his cock throbs with need as Castiel wastes no time and starts fucking into his ass at a rapid pace.

Dean can only describe the way their bodies come together as frenzied and wild, almost animalistic in its nature. Castiel punches the breath out of his lungs with every thrust of his cock, clutching him roughly by the hips as he pulls Dean’s ass to meet him. Moan after moan spill from Dean’s open mouth, and he clenches around Castiel, feeling his balls draw tight as his pleasure escalates, his orgasm building steadily under his skin. The sound of their skin slapping together is music to his ears, punctuated by Castiel’s breathy grunts and his own needy sounds.

At one point, Castiel slams into Dean so hard that the impact shoves him up the bed, knocking him down before he can compensate, but then Castiel is climbing over him in a flash, bracketing Dean’s hips with his knees. He sinks inside Dean once more, driving his cock even deeper as he resumes his punishing rhythm. Dean cries out, tears stinging his eyes as the change of angle allows Cas to nail right into his prostate, sending waves of white-hot pleasure to his groin with every slide of Cas’ cock.

Castiel grabs the back of Dean’s splayed hands, clutching his wrists with a tight grip and pressing down on them as he continues to fuck Dean into the mattress. A part of Dean wonders if Cas might leave bruises on his wrists, and he finds himself wishing that he would. They’d go well with the ones on his neck and his rear, he thinks—if the faint, continuous sting in his skin is anything to go by.

It’s to the thought of Castiel leaving him marked with bruises and his come that Dean’s orgasm suddenly slams into him, shouting a mantra of _Cas, Cas, Cas_ as he spurts rope after rope of come onto their bed, the sharp, electrifying rush of his climax turning him boneless as it washes over him. Castiel fucks him through it, grinding into his tight heat until he comes with a low, drawn-out groan. The rolling of his hips slows down as he spills inside Dean, fucking his slick channel a couple more times before he comes to a stop with a slow, final thrust.

They take a moment to catch their breaths, panting loudly in the pleasant silence as they come down. Castiel leans down, pressing a kiss to the back of Dean’s neck before he pulls out, making Dean groan lowly at the still stimulating drag of his cock. Cas chuckles knowingly, lifting himself off Dean to allow him to twist around. Dean meets Castiel’s blue gaze with a fucked-out smile once his back is pressed against the bed, but then makes a face at the feeling of his own come smeared on the skin of his back. Cas huffs a laugh at his expression, but Dean quickly surges up to capture his mouth in a slow, open kiss, uncaring of the sticky mess, floating in the afterglow.

Castiel tastes sweet, like home, and Dean falls back on the bed when he gets his fill, grinning blissfully at Cas. “God _damn_ , Cas, that was incredible,” he says, breathless. “We haven’t fucked like that in a while.”

Castiel smiles back and dips down to kiss along his jaw. “Let’s just say the mood suddenly struck,” he breathes against Dean’s skin.

“Well, I hope it does more often, then,” Dean says, winking up at Castiel when he draws back. He slides his hands up and laces his fingers with Cas’, craving his closeness and comfort after their rough, mind-blowing lovemaking, but then something makes him pause, his brow furrowing on its own before he realizes that he can’t feel the familiar shape of Castiel’s ring between his fingers.

Twisting his head to the side, Dean’s gaze lands on their joined hands, finding that Cas' ring is, indeed, missing.

“Hey,” Dean says, uncertain. Castiel _never_ takes his ring off, not even when he asks him to help him with Baby occasionally. “Did you lose your ring?”

“Oh.” Castiel merely glances at his hand. “It must’ve slipped off while I was downstairs,” he adds with a shrug.

"Hm. Weird," Dean says, mostly to himself. He looks up at Cas again. “Well, c’mon. Let’s go look for it before the Roomba sucks it up or something.” He then shifts to sit up, accidentally bumping his knee against Castiel’s injured hip when he tries to bring his leg up. “Shit, my bad” he adds quickly, mentally chastising himself for his carelessness. “I’m sorry, Cas, I didn’t mean to…”

Dean trails off when Castiel doesn’t react; doesn’t even flinch or hiss in pain like he had for the past few days after his injury. Puzzled, Dean’s frown deepens, and his eyes slide from Castiel’s impassive expression down to his hip.

The dark, purplish bruise that adorned his skin is...gone.

Dean blinks, but the unblemished skin remains unchanged. Bewildered, he looks up at Cas again, his mind racing as he tries to make sense of his missing bruise. Cas watches him silently, and Dean opens his mouth to speak, but the words won’t come out—they remain trapped in his throat, doubt paralyzing him as the skin at the back of his neck prickles faintly.

His ears then pick up a sound from outside, and Dean recognizes it as the quiet hum of an engine before a car drives past their house. Its headlights shine through the windows, flooding their dimly lit bedroom with a glaring beam before it disappears as quickly as it had materialized, but in that brief second, Dean sees the way it catches the deep blue of Castiel’s eyes, the light somehow reflecting from his irises—they flash an eerie shade of silver, pale as a polished bone, shimmering like water under a full moon, and then it’s gone, replaced by blue once again, calm and clear and collected, as if it nothing at all had happened.

Dean’s chest sinks into itself at that moment, leaving behind a pit that swallows him whole. The words stuck to his throat are finally shaken loose, spilling from his mouth into the space between them as his eyes widen with fear.

“You’re not Cas.”

His voice is nothing more than a whisper, but he knows Castiel hears him when he tilts his head to the side slightly, regarding him, and the mannerism is so familiar that it makes Dean hesitate for a moment, unsure all of a sudden.

The rational part of his mind, the one still clinging to logic and reason, starts to doubt what he had seen, and Dean questions himself, tries to quiet that voice at the back of his mind screaming at him to run. Dean knows he’s exhausted, feels the hazy tiredness that always follows the high of an orgasm in his limbs, and he’s pretty sure being so abruptly woken up from sleep is seriously compromising his senses. He wouldn’t be surprised if he’d just imagined that strange reflection in Castiel’s eyes, especially since he knows that such a thing is _impossible_ in human physiology. It had been simply a mirage, a fabrication of his mind—perhaps even the car itself, equipped with an uncommon set of headlights.

He then remembers Castiel’s bruise—or lack thereof. There’s probably a good, logical explanation for it as well. Maybe the bruise had already healed and Dean failed to notice, and Castiel had just been teasing him about it earlier. It checks out—after all, Cas hadn’t passed an opportunity to bring it up whenever he could, complaining about it with his typical sarcastic remarks. There was no real heat or malice behind them of course, and Dean knew Cas only did it to poke fun at him, which means that tonight probably was no different from those other times.

And the ring—well, that’s probably the easiest one to figure out, Dean thinks. People often misplace or lose their wedding rings for dozens of different reasons and don’t notice immediately. It can happen to anyone, really. It’s what must have happened to Cas. 

Right?

Doubt creeps in once more, slipping through the cracks of his carefully constructed reasoning like poison, and Dean feels it crumble as the seconds tick by, breath caught in his throat.

Castiel watches him from above for an endless moment before something changes in his eyes, the spark in his pupils fading like a flame reaching the end of a wick, leaving an unrecognizable darkness behind when it fizzles out of existence. His lips twitch, curving upwards until a sinister smirk splits his face, twisting his features until Dean can barely recognize them. The air rushes out of Dean's lungs in a shuddering breath at the sight of it, his mouth turning dry in an instant, and he shakes as a chill runs down his spine when the horrifying realization that this is, in fact, _not Cas_ , sinks in.

Terror sinks its cold, jagged teeth into every cell of Dean’s body, tearing through muscle and bone until he feels he might never feel warmth again, and he remains frozen to the spot, incapable of movement. Cas—no, _Not Cas_ —simply observes him with a sadistic glint in his eyes, his grin turning slightly amused as Dean stares at him with growing horror, chest heaving with shallow, panicked breaths.

The weight above Dean feels oppressive, suffocating, as does the tight grip around his hands, and his instinct to run, to protect himself, kicks in all of a sudden. Dean whirls his head to the side, searching for something, _anything_ to use as a weapon and bash this—this _thing’s_ head right into its fucking skull, and his frantic gaze settles on his own unlit lamp atop his nightstand, almost within his reach.

He doesn't hesitate this time, quickly yanking his hands free from Not Cas' and lunging for it.

A hand suddenly grips Dean by the hair before he can wrap his fingers around the lamp, shoving his head violently against the wooden headboard of the bed. There’s a loud crack the instant Dean’s head connects with it, the sound echoing around his mind until it turns into an incessant ringing. Dean feels his body go limp as pain blooms from his temple, hot and sharp and disorienting, making his vision swim in and out of focus briefly before the world fades to black.

**Author's Note:**

> STORY TIME: so a few months ago, as me and my s.o. were getting ready to sleep, they suddenly got up to check on something outside of our bedroom. i then slipped my sleep mask on and was on the verge of sleep when they returned sometime later, but then as they climbed back onto the bed, a voice whispered in my mind "how sure are you that it's them next to you?", which ofc led me to rip said mask off my eyes to check that it was really them. it was super messed up, and it's probably a sign that I should stop watching horror movies at night, but then I thought this would make an interesting deancas!au, and so this fucked up thing was born.
> 
> i'm in the process of editing chapter two, so hopefully i'll have it ready in the next few weeks. *spoiler alert* things are going to get so, so much worse. 
> 
> anyway, thanks for reading! let me know what you think. [my tumblr](http://gracefuldean.tumblr.com/)


End file.
